Decontamination shelters partitioned to provide a succession of compartments for disrobing in order to remove contaminated clothing, showering to rinse off any contaminant and redressing are known. Openings provided with closures are provided between compartments to permit passage from one compartment to the next. Such structure has the disadvantage that as a worker proceeds from one compartment to the next, there is direct communication between compartments so that the contaminants can flow through from one compartment to the next unimpeded and, in addition, movement of the worker from one compartment to the next displaces the contaminants from one compartment to the next. It is the purpose of this invention to provide a decontaminant shelter wherein there are locks or dead spaces between compartments which may be secured to prevent direct transfer of contaminants from compartment to compartment during the progress of the worker from one compartment to the next, thus to provide maximum security against transfer of contaminants from the contaminated area into the shower area and from thence into the dressing area.